This patch-set makes ext4 independent of the VFS superblock management services. Namely, ext4 does not require to register the 'write_super()' VFS call-back. The reason of this exercises is to get rid of the 'sync_supers()' kernel thread which wakes up every 5 seconds (by default) even if all superblocks are clean. This is wasteful from power management POW (unnecessary wake-ups). Note, I tried to optimize 'sync_supers()' instead in 2010, but Al wanted me to get rid of it instead. See https://lkml.org/lkml/2010/6/6/87 And I think this is right because many file-systems do not need this, for example btrfs does not use VFS superblock management services at all, so on a btrfs-based system we currently end-up useless periodic wake-ups source. Changes for other file-systems are coming later. The patch-set structure. 1. patches 1,2,3 are independent ext4 cleanups and I ask Ted to merge them as soon/long as they are OK. I sent them also independently in order to get early comments, but did not get so far, so re-sending. 2. patch 4 exports 'dirty_writeback_interval' and it would be very useful to have it merged ASAP to simplify further work 3. patch 5 is also and independent VFS clean-up 4. patches 6-9 actually make ext4 independent on the 'sync_supers()' thread. Thanks, Artem. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
